Printing heads of this type, known as "interleaved bipolar heads with two common conductors" are well-known to persons skilled in the art.
Although the use of two current input conductors (the two "common conductors") enable the design of these thermal heads to be simplified, the electrical supply to these heads has, up to the present time, required the use of relatively complex and expensive circuits, which notably restrict development of this type of head.
In particular, when the supply originates from an alternating voltage source, the supply circuits normally include a means of filtering and regulation, intended to provide the head with a constant and uniform supply of electrical energy at all times.